Question 768133: Please can you answer this question
A bus travels uniformly from 54 km/h to 72 km/h in 10 seconds. Find the
(a)acceleration in m/s^2
(b)distance travelled by the bus
ANSWER
I did the first one. Please tell me is it correct and can you tell me the second one.
Initial velocity, u = 72 km/h = 72×(5/18) m/s = 20 m/s
Final velocity, v = 54 km/h = 54×(5/18) m/s = 15 m/s
Time in which velocity changes is, t = 10 s
Acceleration, a = (v - u)/t
=> a = (15 - 20)/10 = -0.5 m/s^2
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! A bus travels uniformly from 54 km/h to 72 km/h in 10 seconds. Find the
(a)acceleration in m/s^2
(b)distance travelled by the bus
ANSWER
I did the first one. Please tell me is it correct and can you tell me the second one.
Initial velocity, u = 72 km/h = 72×(5/18) m/s = 20 m/s
Final velocity, v = 54 km/h = 54×(5/18) m/s = 15 m/s
Time in which velocity changes is, t = 10 s
Acceleration, a = (v - u)/t
=> a = (15 - 20)/10 = -0.5 m/s^2
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Looks right, except you swapped the initial and final speeds.
--> + 0.5 m/sec/sec
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(b)distance travelled by the bus
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Its avg speed over the 10 sec is (15 + 20)/2 = 17.5 m/sec
17.5*10 = 175 meters
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